The present invention relates to tire chains and more particularly to a novel chain tightener for tightening and locking heavy-duty tire chains mounted on large tires such as truck, bus or construction equipment tires.
Prior art chain tighteners developed for fastening and locking tire chains on tires generally include some type of caming element which interconnects opposed end links of one of the perimeter chains of a tire chain. The caming element may be suitably manipulated, either by a tool or an individual's fingers so as to be shifted into a locking position. Generally, chain tighteners which do not utilize special fastening tools include some type of shiftable clasp or deadlock for securing the caming element. Unfortunately, clasps may become damaged or corroded rendering them difficult to use.
Such a chain fastener is exemplified in Stahl, U.S. Pat. No. 1,851,460 which describes a cam lever connected to an end link of one end of a side or perimeter chain. The cam lever may be suitably inserted through an end link of the opposite end of the perimeter chain and pivoted so as to draw the two ends toward one another. A projection on the cam lever is ultimately inserted through an adjacent link so that a keeper, slidably mounted on the link may be positioned over the projection to lock the cam lever in position. Further prior art devices utilizing this same general principal include, amongst others, Thomas (U.S. Pat. No. 1,816,941), Myers et al (U.S. Pat. No. 2,153,003), Stahl (U.S. Pat. No. 2,123,864), St. Pierre (U.S. Pat. No. 2,162,670) and Tawney (U.S. Pat. No. 1,310,456). Additionally, there are disclosed in prior U.S. patents chain tighteners which utilize some type of hook or connecting element on the end of a cam lever to maintain the cam lever in a locked position. Exemplary of this concept are Fox (U.S. Pat. No. 934,154), Howg (U.S. Pat. No. 1,419,565) and Heinecke (U.S. Pat. No. 1,866,889). A tire chain fastener is also disclosed in Hubble (U.S. Pat. No. 1,418,149) which utilizes, in one embodiment, a sinuous-shaped hook manually positionable through an end link of a chain for drawing the ends of the chain together.
With respect to large heavy-duty tire chains, such as those used on truck tires, it can be appreciated that tightening of the tire chains is a difficult chore requiring substantial effort to draw the ends of a perimeter chain toward one another. To this end, it has generally been the practice to utilize special types of tools or wrenches which may be connected to cam-like tighteners for effecting tightening action. Of course, it can be appreciated that such tools can become lost or broken and are generally inconvenient. It is apparent that if a chain tightener could be utilizied without the necessity of tools and operable for manually tightening a truck tire chain, such a chain tightener would be extremely advantageous.
Additionally, in the case of truck tire chains, it is necessary to provide a chain tightener which is strong enough for holding ends of a perimeter chain together but which maintains a relatively low profile. Stated differently, the chain tightener must not extend beyond the perimeter chain an amount which would result in the tightener contacting the road. Such contact would result in damage to the chain tightener and could impair it from its normal operation. Additionally, the profile of the chain tightener becomes important when it is recognized that cross chains on truck tire chains have been shortened thereby drawing the perimeter chains of the tire chain closer to the road engaging surface of the tire.
Accordingly, it is a general object of the present invention to provide a novel chain tightener for interconnecting opposed end links of a perimeter chain of a tire chain mounted on a tire which includes an arcuate handle member having a free end and a lug end with the lug end being pivotally connected to an end link of the perimeter chain. The arcuate handle is dimensioned for complete gripping by an individual's hand so that when the free end of the arcuate handle is inserted through an opposed end link on the perimeter chain, an individual may rigidly grip the arcuate handle and force it toward the other side of the perimeter chain thereby providing camming action drawing up the perimeter chain. The free end is then inserted into a receiving link in a locked position. A catch means or notch is disposed adjacent the lug end and receives and holds the opposite end link when the perimeter chain is in the locked position.
Another object of the present invention is to provide a chain tightener, as described above, in which the lug end is provided with an eyelet for pivotally receiving the end link and wherein the catch means includes a notch having a circular portion configured for nesting the opposite end link in the locked position. The eyelet and the notch are positiond relative to one another so that an imaginary line interconnecting their centers and extended toward the free end is spaced from the free end. This configuration results in a low profile when the chain tightener is in the locked position.
Still another object of the present invention is to provide a chain tightener, as described above, in which the arcuate handle member, which doubles as a cam lever, is dimensioned with opposed concave-convex sides, with the concave side being generally defined by an arc having a radial dimension residing in the range of about 2 to 31/2 inches. With the arc length of the handle member being dimensioned generally in the range of about 3 to 5 inches, sufficient handle area is provided for complete gripping or grasping by an individual with the handle member held in the palm and gripped firmly thereagainst by the fingers. With a firm grasp on the handle member, an individual may impart sufficient force to cam the chain tightener into a locked position.
These and additional objects and advantages of the present invention will become more clearly understood from a consideration of the drawings and the following detailed description of the preferred embodiment.